Liquid level gauge



G. J. vOESTREIcI-IER 2,182,749

LIQUID LEVEL GAUGE Original Filed June 25, 1936 2 Sheets-Sheet l f-ATTORNEY.

Dec. 5, 1939. f G. J. oi-:sT'R-EICHER LIQID LEVEL GAUGE original Filed June 25, 193;

HELE. m

1 elly/065;

2 Sheets-Sheet 2 INVENTOR.

EEDREE J. UESTREIBHER.

BY h

/ATTORNEK Patented Dec. 5, 1939 NETE!) STATES LIQUID LEVEL GAUGE George J. Oestreicher, Cleveland, Ohio Application June 25,

1936, seal- Nn., 87,267.

Renewed October 17, 1939 4 Claims.

This invention relates to liquid levelv gauges for the visual indication of liquid levels in tanks and receptacles and particularly to a portable gauge which can be attached to and removed from tanks and receptacles in which the liquid level is to be gauged.

One of the principal objects of the vpresent invention is to providea compact and sturdyA gauge for this purpose which gauge is self-contained and portable and so constructed that it may be bodily attached to or disconnected from a receptacle while in completely assembled condition, by operating a single manually operated nut.

An equally important object is to provide a portable gauge which, when necessary, may be quickly disassembled for cleaning and as readily reassembled without any tools.

Another object is to provide a glass tube gauge which may be made in greater lengths than heretofore considered practicable and in which -the glass tube is protected against stresses due to shocks, expansion, contraction and the like.

A specic. object is to provide a gauge in which the glass liquid tube is both sealed and supported solely by rubber, or similar resilient material, out of contact with any of the harder metal parts as a resulty of Which differentials in expansion and contraction between the metal portions and the glass can cause no damage to the glass tube.

Another specific object is to provide elements by which the tube is clamped in place in a manner Such that uniform radial pressure only is exerted thereon and axial and angularly directed pressures and forces, due to misalignment of the parts and unequal application on the resilient tube supporting elements, is. prevented.

Other objects and advantages will become apparent from the following specification wherein reference is made to the drawings in which Fig. 1 is a front elevation of a plurality of tanks with the connections for attachment of the gauge thereon and with the gauge in operating position with respect to one of the tanks;

Fig. 2 is an enlarged vertical sectional view of the gauge and attachment taken on a plane indicated by the line 2-2' in Fig. 1;

Figs. 3, 4, and 5, are cross sectional views taken on planes indicated by the lines 3 3', 4 4, and 5--5, respectively, in Fig. 2;

Fig. 6 is a side elevation partly in section showing the portable gauge in partly disassembled condition;

Fig. 7 is a side elevation of the upper portion of the gauge showing an adapter for use in con- (ol. vs -3255 nection with the receptacles in which the liquid is under pressure; and

Fig. 8 isa fragmentary sectional view of the gauge .illustrating a rnoditlcation of the attaching means therefor.

While thepresent gauge may be installed in a main which is common to a number of tanks, the tanks being connected'to the main through the medumof cut-of` valves so the tanks can be connected selectively or concurrently thereto, the advantages of the gauge will become more apparent'from -a description of theA following illustrative example. Furthermore, while the present gauge may be used for gauging the liquid level in steam boilers, `beer `vats, and on other types of vats, its present advantages are most Clearly disclosed inconnection with the gauging of milk receptacles in, which the necessity for extreme cleanliness of all parts andprovison for quick and thoro-ughl cleaningmust be provided.

For thepurposesl or illustration, therefore, the gauge is shown for use in connection with a plurality of milk tanks l which are connected to a commony main 2l` Since quite often in the milk industryan'extremely large number of tanks vare connected to a vcommon main, it is inadvisable to cut `oif the ow through the main at any time with the result that provision must be made for gauging each tank while the common main is open instead` offusing a single gauge in the main for all tanks, In such industrial installations, there is provided between each tank and the common main, a suitable cut-01T valve 3 so that each may be independently disassociated from the main. Such tanks are usually glass lined and it is inadvisable to install any gauge or tting which ,necessitates` cutting of the glass lining. Conscquently, the usual connection to the main is provided, between the cut-off valve 3 and the tank, with a suitable T-connection 4. Such connections are customarily provided with external threads permitting connection thereto ofthe usual lre hose type of connection.

Referring to Fig. 2, there is illustrated a gauge receiving socket, vdesignated generally as 5, and having at onejend an internally threadedre hose couplingY element 6 arranged for connection with the threaded end of the T-connection 4 so that the socket 5 can. be readily connected thereto Without the exposure of any threads to the milk.

The socket 5 has a straight longitudinal duct 1 extending entirely therethrough from end to end and preferably of the same diameter throughout its entire length. Intermediate its ends, the socketl has ka transverse Atapered bore il which55 extends entirely therethrough and intersects the duct 1 centrally. The bore 8 is adapted to receive the lower end of the portable gauge, later to be described. Between the tapered bore 8 and the inlet end of the duct 1, the socket is provided with a transverse bore extending at right angles to the bore 8 and to the duct 1 and intersecting the latter, this bore accommodating a tapered plug 9 of a stop cock. The plug 9, in turn, is provided with a bore of the same diameter as the duct 1 so as to form a continuation thereof when the plug 9 is rotated to an open position. The bore which accommodates the plug 9 likewise extends entirely through the socket so as to be readily cleaned.

At the opposite end of the duct "I, the socket 5 is provided with a suitable plug cap I0 having a knurled outer surface so that it may be readily detached manually for permitting ready access into the duct 'I. In the form illustrated, the plug cap IIJ carries a drain cock II which, before removal of the gauge from the socket 5 may be opened to drain any liquid entrapped in the gauge proper. The socket member 5 is mounted on the T-connection 4 and is removed only for purposes of cleaning.

Referring next to the portable gauge proper, the gauge includes a rigid, self-supporting, metal shield or body I5. The shield is preferably formed from a single continuous piece of material turned and formed so as to provide an outer portion I5a which, in cross section, is substantially a circular segment greater than a semi-circle and an inner portion I5b preferably concentric with the outer portion I5a and having its walls parallel thereto. The portion I5b is open slightly infront, as indicated at |5c, so that the glass tube of the gauge, which is positioned within the inner portion of the shield, is readily visible. The resultant shield is therefore a hollow, double-walled shield of U-shaped cross section affording an extremely rigid structure with an insulating pocket of air between the portions I 5a and |512. Thus the shield itself cannot readily be iiexed or sprung when moved from place to place so as to pinch and fracture the tubing. Likewise it protects the tube from chilling blasts of air which, when the tube is hot, would be apt to cause too sudden contraction of the tube and breakage thereby. The shield I5 is of uniform cross section throughout its length and open at both ends.

At the upper end of the shield is a header I6 having a depending boss Ilia which lits within the shield and lies snugly along the inner face of the wall of the outer portion I5a and is preferably coextensive circumerentially therewith to a point beyond the diameter so that the header is retained in fixed radial position with respect to the shield. A suitable screw I'I may be utilized to secure the header in position. The header has an upturned annular ange portion I6b which is internally threaded for receiving an externally threaded clamping element I8. The header I B has an axial passage I9 coaxial with the shield portion |513 and has a counterbore 20 of larger diameter than the passage and receiving an expansible resilient washer 2| of rubber or similar material. The clamping element I8 likewise has an axial passage 22 coaxial with the passage I9 and preferably of the same diameter. Both the passages 28 and 22 extend entirely through their associated members and form a continuation of the passage defined by the inner portion I5b of the shield when the members are in operating position.

On the lower end of the clamping element I8 there is provided an annular boss 23 which is slightly less diameter than the counterbore 20 and substantially the same depth as the counterbore. 'Ihe boss 23 is accurately formed on the element I8 so that, when the element I8 is screwed into the header I8, the boss 23 will be coaxial at all times with the counterbore 20. The glass gauging tube 24 lies within the inner shield portion I5b in slightly spaced relation to the walls thereof, as better illustrated in Fig. 3, and extends through the passages I9 and 22 with slight radial clearance. Since this clearance is necessarily slight, the tubing when installed and clamped in place must retain its concentric position.

For effecting the installation, the tubing is slid through the passage I9 and the washer 2| is placed thereon and lightly pressed into the counterbore 2D whereupon it accurately centers the tube 24. The washer is preferably of the same dimension axially as the depth of the counterbore and the washer, the boss 23, and the counterbore 2D are considerably smaller in diameter than the threaded portion of the element I8. Thus there is never any danger of the washer being subjected to contact with the threads when expanded radially by axial pressure of the boss 23. Furthermore, due to the limited radial dimensions of the boss and washer, the element I8 may be more readily rotated for screwing it into position, as T the surface between the boss 23 and the Washer 2| is reduced to a minimum and reduces frictional resistance to rotation, the stress on the washer is concentrated and applied absolutely axially on the washer and at absolutely the same distance from the tube at all points about the washer, and the lever arm eiective at the outer radial limits of the element I8 is relatively greater. Consequently, the washer 2| is expanded uniformly and to a high degree by hand operation of the element I8 and the slight radial clearance alforded between the tube 24 and the passages I9 and 20 is maintained uniform entirely around the tube. This clamping pressure is so great that the tube cannot be removed except by loosening the element I8, yet it is supported entirely by the washer 2| and is entirely out of contact with any metal.

If desired, the tube can extend entirely through the element I8 and thereabove, as illustrated in Fig. 2, as it preferably is not seated against any abutment at its ends. At the opposite or lower end of the shield I5, a header 39, corresponding in form and function to the header I6 above described is provided, the tube 24 extending therethrough and being similarly retained in place by an expansion Washer 3|. Instead of the element I8, however, a connecting element 32 is utilized, the upper end of this element being provided with a boss 33 for expanding the washer and being externally threaded for threaded engagement with the header 30. rihe axial passage 34 of the element 32, while not extending entirely therethrough, extends beyond the lower end of the tube 24 so that the tube is subjected to no axial stresses by engagement with the unyielding end abutments and is not confined axially except by the resilient washers.

The connecting element 32 has a depending tapered portion 32a which is received in the tapered bore 8 of the socket The tapered portion 32a, however, does not t the bore 8 but is` of slightly less diameter to provide radial clearance, as indicated at 35. The portion 32a has a transverse duct 38 of the same diameter as the duct 'I so that whenv the gauge is installed in the socket and properly aligned',` the ductf36 may form a continuation of the duct l. However, since the gauge may be rotated slightly out of proper position, an annular channel 39 is provided on the portion 32a for connecting the duct 35 with the duct 'i in any rotated position of the gauge, and through the bore 34 of they connection 32 with the tube l2li. The lower end of the portion 32a, extends beyond the lower end of the bore 8 and socket 5 and is threaded externally to receive an internally threaded cap 40; The cap has a suitable packing or resilient sealing washer @l which engages a shoulder on the lower portion of the connection 5 when the cap is screwed into place for effecting sealing engagement therewith. Correspondingly, a shoulder 42 is provided at the upper end of the tapered portion 32a and a cooperating shoulder is provided on the socket 5.a resilient washer 43' beingv disposed between the latter shoulders and compressed by the cap li!! concurrently with the washer el for sealing both ends of theybore 8.

The element i S, the cap lit, and the connection 32 are provided with knurled surfaces of large diameter so that they can be readily screwed and unscrewed by hand pressure to a degree sufficient for expand-ing the associated washers properly.

To remove the gauge from. the socket 5, it is only necessary to close the stop cock 9, open the stop il to drain the tube-2, and then re move the cap lil and lift the gauge out of position. For cleaning the socket 5, the cap l may 35 be removed, the stop cock 9 turned to open position and the duct 'i cleaned readily, since it is of substantially constant diameter and open throughout its length. Obviously the bore 8 can be readily cleaned as it is likewise accessible from blo-th ends. To clean the portable gauge itself, it is only necessary to detach the element 32 by hand., leaving the tube 24 installed in the shield i5. The tube may be readily cleaned from either end. The element 3,2, itself, havingonly a single transverse duct and a single intersecting longitudinal duct, both. of which are readily accessible, may be cleaned easily. Replacement of the tube 2li may also be accomplished without tools, as is apparent.

In the case ci extremely long gauges, it is often desirable that they be supported by the tank or other suitable support as well as by the socket, and for this purpose a clamp 45 is provided. The clamp is mounted on the tank or any other suitable support. This clamp comprises yoke arms 65a which snugly receive the shield l5 and a closure bar 45h which is detachably secured thereto by wing screws Mi. The bar is preferably slotted at one end, as indicated at 41, so that by loosening only one wing screw it may be swung out of position for removing the gauge.

As best illustrated in Figs. l and 3, there is provided on. the forward face of the shield I alongside the tube 2li an aluminum strip 50, the strip 5I) being pro-vided for marking the calibration of the gauge. To calibrate the gauge it may attached to the particular tank with which it is to be associated and the tank filled, and then a weighed or measured amount of liquid withdrawn, the liquid level mark being scratched on the strip 5t and marked, after each withdrawal. The marking may be in such units as appear necessary for the particular use. If a single gauge is to be used with two tanks and left permanently in the line except for cleaning, two

oneI tank and oner for the other, unless the tanksl happen to be duplicates. On the other hand, it is quite often desirable to mount the strip 5D directly -on lthe tank, so that the gauge itself discloses only the liquid-level, the calibrated strip bei-ng positioned to be read for the particular tank.

Tousea gauge in r connection with tanks or receptacles underv pressure, the structure illustrated in Figi? is provided.v In this structure the upper end of the gauge is closed by` a suitable closure element Gil, corresponding insofar as the clamping of the glass tube BI is concerned with the element i8 heretofore described and being substituted for the element I8. Fixed in the upper end of theelement Si)` is a suitable tube 62 which is in sealed relation with the element 60 and has a gas et sealed upper end, not shown, adapted for cooperation with a knurled nut 53.. The nut 63 iscarried on a suitable tube 64 which is connected with a suitable cut-off Valve 55, the opposite side of which valve is connected to a coiled conduitline t5. 'Ihe conduit line 66 is connected, in turn, toa 'receptacle El above the liquid level, Thus by closing the valve 65 and the usual cut-olf Valve on the gauge socket, the gauge can be readily removed and reconnected. Expansion and contraction, of course, are compensated through the medium of the coiled tube 6a. .l

Referring next to Fig. 8 a modified connection of the bottom end of the gauge with a pipe line is illustrated. Most industrial tanks and receptacles are provided with pipes 10, such as`the pipe 2 heretofore described, on the ends of which are T-connections 1| and suitable drain cocks 12, the cocks 12 being fastened on one part of the T-connection.` The other part of the connection receives a threaded adapter 13 4which generally 'remains fastened thereto. vIn the upper end of the adapter, a suitable counterbore 14 is formed which receives a sealing washer 15 and conforms, in general, to the counterbore heretofore described. However, instead of being formed in the connecting elements of the gauge this counterbore is formed directly in the adapter T3. At the lower end ofthe gauge, instead of the connecting element 32, a connecting element or connecter 16 is provided which has an outer knurled portion and a threaded portion 16a adapted for threaded cooperation with the header 1T of the gauge and a central press fitted portion 1Gb which has an axial duct for accommodating the lower end of the glass tube 19 with radial and axial clearance. The press fitted portion 1Gb extends beyond the connector 16 at each end, the upper end forming the boss portion 16o for cooperation with the tube retaining washer 80. The lower end of the portion '15b is provided with a shoulder on which operates a hand operated nut 8| which is threaded internally for cooperation with the upper threaded end of the adapter '13. ThusA by hand pressure, the nut 8| can be rotated for drawing the portion 1Gb tightly against the washer 15 for expanding the same, thus sealing between the portion 1Gb and the adapter 13 so that a continuous passage for the glass tube into the T-connection 1I is provided. Necessarily, in the line 1B, the usual cutoff Valve is provided in advance of the T-connection so that the tank can be readily disconnected therefrom. For removing the gauge in this instance, it is only necessary to loosen the one hand nut 8| and lift the entire gauge free ofits connection. The adapters 13 are connected in each line and when the gauge is removed, a suitable cap can be screwed thereon for sealing the adapter until again ready for use, as desired.

Having thus described my invention, I claim:

l. In a gauge of the character described, a glass tube, a rigid self-supporting shield body having an inner wall portion in substantially surrounding and closely spaced relation to the tube and a continuing outer wall portion spaced from the inner wall portion and dening a peripherally closed air insulating space therebetween, means carried by the body and securing the tube thereto in said spaced relation, and connecting means for detachably connecting the tube to a conduit with said tube in communication with the conduit.

2. In a gauge of the character described, a glass tube, a rig'id self supporting shield body having inner. and outer wall portions of substantially U-shaped cross section and joined to denne a peripherally closed air space, said inner wall portion partially surrounding the tube in closely spaced relation'to the tube, means carried by the body for securing the tube thereto in said spaced relation to the inner wall surfaces, and connecting means for detachably connecting the tube to a conduit with the tube in communication with the conduit.

3. In a gauge of the character described, a glass tube, a rigid self supporting hollow double wall shield in substantially surrounding and closely spaced relation to the tube, headers having flange portions accommodated between the walls of the shield at the ends and having end portions overlying the ends of the walls, means cooperable with said headers respectively for supporting the tube in said spaced relation to the shield, and connecting means for detachably connecting the tube to a conduit with said tube in communication with the conduit.

4. In a gauge of the character described, the combination of a glass tube which is open at its upper end,la shield for the tube extending lengthwise of it and comprising inner and outer w'all portions which are spaced apart and connected to form an insulative air space between said portions, the inner of said portions partially encircling the tube, close thereto, said portions extending toward each other from opposite directions adjacent one side of the tube and spaced apart to expose a portion of the tube for enabling reading of the gauge, a header for the lower end of the shield, yielding means associated with the header for supporting the lower end of the tube out of contact with the header and the shield, means associated with the header for connecting the interior of the tube with a conduit adapted to communicate with a tank or like space to be gauged, and yielding means associated with the upper end of the shield for supporting the upper end of the tube.

GEORGE J. OESTREICHER. 

